The analysis, using data from more than 100 countries spanning nearly two decades, indicates that increased air pollution is linked with rising antibiotic resistance across every country and continent.
It also suggests the link between the two has strengthened over time, with increases in air pollution levels coinciding with larger rises in antibiotic resistance.
"Our analysis presents strong evidence that increasing levels of air pollution are associated with increased risk of antibiotic resistance," researchers from China and the UK wrote. "This analysis is the first to show how air pollution affects antibiotic resistance globally." Their findings are published in the Lancet Planetary Health journal.
Antibiotic resistance is one of the fastest-growing threats to global health. It can affect people of any age in any country and is already killing 1.3 million people a year, according to estimates.
The main drivers are still the misuse and overuse of antibiotics, which are used to treat infections. But the study suggests the problem is being worsened by rising levels of air pollution.
The study did not look at the science of why the two might be linked. Evidence suggests that particulate matter PM2.5 can contain antibiotic-resistant bacteria and resistance genes, which may be transferred between environments and inhaled directly by humans, the authors said.
Air pollution is already the single largest environmental risk to public health. Long-term exposure to air pollution is associated with chronic conditions such as heart disease, asthma and lung cancer, reducing life expectancy.
Short-term exposure to high pollution levels can cause coughing, wheezing and asthma attacks, and is leading to increased hospital and GP attendances worldwide.
Curbing air pollution could help reduce antibiotic resistance, according to the study, the first in-depth global analysis of possible links between the two. It also said that controlling air pollution could greatly reduce deaths and economic costs stemming from antibiotic-resistant infections.
